Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and the air/fuel mixture is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive various components of the gas turbine engine.
Turbines typically include alternating stages of static vane assemblies and rotatable wheel assemblies. The rotatable wheel assemblies include disks carrying blades that are coupled to the disks. When the rotatable wheel assemblies turn in response to receiving the combustion reaction products, tips of the blades move along ceramic blade tracks included in static turbine shrouds surrounding the rotating wheel assemblies; thereby, work is extracted in the form of mechanical energy.
To maximize the mechanical energy extracted by the turbine, seals are arranged at circumferential interfaces between adjacent segments of the blade track to block leakage of combustion products through the blade track. The seals are sometimes located by slots formed in the blade track segments. Exposure of ceramic blade track segments to the combustion reaction products can result in the degradation of the blade track over time. Coatings are sometimes used to protect ceramic gas turbine engine components. However, applying coatings to the ceramic blade track segments inside seal-locating slots can present design and manufacturing challenges.